Fluorine-containing monomer, fluorine-containing polymer and surface treating agent

ABSTRACT

Disclosed is a fluorine-containing polymer having: 
     (A) a repeating unit derived from a fluorine-containing monomer which is represented by the following formula: 
       CH 2 ═C(—X)—C(═O)—Y—[—(CH 2 ) m -Z-] p —(CH 2 ) n —Rf  (I) 
     (B) a repeating unit derived from a monomer containing no fluorine atom, and if necessary (C) a repeating unit derived from a crosslinkable monomer. This fluorine containing polymer has excellent water repellency, oil repellency and antifouling property.

CROSS-REFERENCE TO RELATED APPLICATION

This is a Divisional of application Ser. No. 10/594,148 filed Sep. 25, 2006, which is a 371 of PCT Application No. PCT/JP2005/005494 filed Mar. 25, 2005. The above-noted applications are incorporated herein by reference in their entirety.

TECHNICAL FIELD

The present invention relates to a polymer and a treatment which impart excellent water repellency, oil repellency and soil resistance to a textile, a masonry, a filter (for example, an electrostatic filter), a dust protective mask, and a part of fuel cell.

BACKGROUND ART

Hitherto, various fluorine-containing compounds are proposed. The fluorine-containing compounds have the advantageous effects of having properties excellent in heat resistance, oxidation resistance, weather resistance and the like. The fluorine-containing compounds are used as, for example, the water- and oil-repellent agent and soil release agent by utilizing the properties that the fluorine-containing compounds have low free energy, i.e., difficulty in adherence.

Examples of the fluorine-containing compounds used as the water- and oil-repellent agent include a fluorine-containing polymer having repeating units derived from (meth)acrylate ester having a fluoroalkyl group. It is proposed that a (meth)acrylate ester having a spacer which is an organic group positioned between an acrylate group and a fluoroalkyl group is used in the fluorine-containing polymer. Such fluorine-containing polymers having the spacer are disclosed in, for example, U.S. Pat. No. 3,655,732, U.S. Pat. No. 3,773,826, U.S. Pat. No. 3,916,053 and U.S. Pat. No. 5,439,998. These fluorine-containing polymers, however, could not impart sufficient water- and oil-repellency.

Recent study results (EPA Report “PRELIMINARY RISK ASSESSMENT OF THE DEVELOPMENTAL TOXICITY ASSOCIATED WITH EXPOSURE TO PERFLUOROOCTANOIC ACID AND ITS SALTS” (http://www.epa.gov/opptintr/pfoa/pfoara.pdf)) and the like clarify that a PFOA (perfluorooctanoic acid) doubtfully has a potential risk of environmental load. EPA (Environmental Protection Agency of USA) announced on Apr. 14, 2003 that the EPA intensifies the scientific investigation on PFOA.

On the other hand, Federal Register (FR Vol. 68, No. 73/Apr. 16, 2003 [FRL-2303-8]) (http://www.epa.gov/opptintr/pfoa/pfoafr.pdf), EPA Environmental News for release Monday April, 2003 “EPA INTENSIFIES SCIENTIFIC INVESTIGATION OF A CHEMICAL PROCESSING AID” (http://www.epa.gov/opptintr/pfoa/pfoaprs.pdf), and EPA OPPT FACT SHEET Apr. 14, 2003 (http://www.epa.gov/opptintr/pfoa/pfoafacts.pdf) announced that a “telomer” may possibly metabolize or decompose to PFOA. It is also announced that the “telomer” is used in a large number of commercial products including fire fighting foams, care products and cleaning products as well as soil, stain and grease resistant coating on carpets, textiles, paper, and leather.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

An object of the present invention is to provide a water- and oil-repellent agent having excellent water- and oil-repellency.

Another object of the present invention is to provide a fluorine-containing polymer constituting a component in said water- and oil-repellent agent, and to provide a fluorine-containing compound which can be used as a fluorine-containing monomer constituting said fluorine-containing polymer.

Means for Solving the Problems

The present invention provides a fluorine-containing compound of the formula:

CH₂═C(—X)—C(═O)—Y—[—(CH₂)_(m)-Z-]_(p)—(CH₂)_(n)—Rf  (I)

-   -   wherein X is a fluorine atom, a chlorine atom, a bromine atom, a         iodine atom, a CFX¹X² group (wherein X¹ and X² is a hydrogen         atom, a fluorine atom or a chlorine atom), a cyano group, a         linear or branched fluoroalkyl group having 1 to 20 carbon         atoms, a substituted or unsubstituted benzyl group, or a         substituted or unsubstituted phenyl group;     -   Y is —O— or —NH—;     -   Z is —S— or —SO₂—;     -   Rf is a fluoroalkyl group having 1 to 21 carbon atoms;     -   m is from 1 to 10, n is from 0 to 10, and p is 0 or 1.

The present invention provides a fluorine-containing polymer comprising (A) repeating units derived from the fluorine-containing compound (a) described in claim 1.

Also, the present invention provides a surface treatment agent comprising the fluorine-containing polymer and a liquid medium (water and/or an organic solvent).

Further, the present invention provides a method of producing a fluorine-containing compound of the formula:

CH₂═C(—X)—C(═O)—NH—(CH₂)—Rf

-   -   wherein X is a fluorine atom, a chlorine atom, a bromine atom, a         iodine atom, a CFX¹X² group (wherein X¹ and X² is a hydrogen         atom, a fluorine atom or a chlorine atom), a cyano group, a         linear or branched fluoroalkyl group having 1 to 20 carbon         atoms, a substituted or unsubstituted benzyl group, or a         substituted or unsubstituted phenyl group;     -   Rf is a fluoroalkyl group having 1 to 21 carbon atoms; and     -   n is from 0 to 10,         said method comprising, in the presence of a base, reacting an         amine compound of the formula:

H₂N—(CH₂)_(n)—Rf

wherein Rf is the same as defined above and n is from 0 to 10, with an acid chloride compound of the formula:

A-CH₂—CH(—X)—C(═O)—Cl

-   -   wherein A is a halogen atom (particularly a chlorine atom, a         bromine atom or a iodine atom); and

X is a fluorine atom, a chlorine atom, a bromine atom, a iodine atom, a CFX¹X² group (wherein X¹ and X² is a hydrogen atom, a fluorine atom or a chlorine atom), a cyano group, a linear or branched fluoroalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted benzyl group, or a substituted or unsubstituted phenyl group.

EFFECTS OF THE INVENTION

The present invention can give a surface treatment agent excellent in water repellency, water repellency and antifouling property.

BEST MODE OF CARRYING OUT THE INVENTION

The fluorine-containing polymer of the present invention comprises (A) repeating units derived from the above-mentioned fluorine-containing compound (a) (that is, the fluorine-containing monomer (a))

The fluorine-containing polymer of the present invention is a homopolymer or copolymer.

In the case that the fluorine-containing polymer is the copolymer, the fluorine-containing polymer may contain:

(B) repeating units derived from a monomer free from a fluorine atom, and (C) optionally, repeating units derived from a crosslinkable monomer,

in addition to the repeating unit (A).

In the present invention, the repeating unit (A) is formed by the fluorine-containing compound (a) of the formula (I).

In the formula (I), the Rf group is preferably a perfluoroalkyl group. The carbon number of the Rf group may be from 1 to 6, for example, from 1 to 4. Examples of the Rf group are —CF₃, —CF₂CF₃, —CF₂CF₂CF₃, —CF(CF₃)₂, —CF₂CF₂CF₂CF₃, —CF₂CF (CF₃)₂, —C(CF₃)₃, —(CF₂)₄CF₃, —(CF₂)₂CF(CF₃)₂, —CF₂C(CF₃)₃, —CF(CF₃)CF₂CF₂CF₃, —(CF₂)₅CF₃, —(CF₂)₃CF (CF₃)₂, —(CF₂)₄CF (CF₃)₂, —(CF₂)₇CF₃, —(CF₂)₅CF (CF₃)₂, —(CF₂)₆CF (CF₃)₂ and —(CF₂)₉CF₃.

m may be, for example, from 2 to 10, and n may be, for example, from 1 to 10.

Preferably, p is 1 when Y is —O—, and p is 0 when Y is —NH—.

Examples of the fluorine-containing compound (a) are the followings.

CH₂═C(—X)—C(═O)—O—(CH₂)_(m)—S—(CH₂)_(n)—Rf

CH₂═C(—X)—C(═O)—O—(CH₂)_(m)—SO₂—(CH₂)_(n)—Rf

CH₂═C(—X)—C(═O)—NH—(CH₂)_(n)—Rf

-   -   wherein X is a fluorine atom, a chlorine atom, a bromine atom, a         iodine atom, a CFX¹X² group (wherein X¹ and X² is a hydrogen         atom, a fluorine atom or a chlorine atom), a cyano group, a         linear or branched fluoroalkyl group having 1 to 20 carbon         atoms, a substituted or unsubstituted benzyl group, or a         substituted or unsubstituted phenyl group;     -   Rf is a fluoroalkyl group having 1 to 21, particularly 1 to 6         carbon atoms;     -   m is from 1 to 10, and n is from 0 to 10.

Specific examples of the fluorine-containing compound (a) are followings:

CH₂═C(—F)—C(═O)—O—(CH₂)₂—S—Rf

CH₂═C(—F)—C(═O)—O—(CH₂)₂—S—(CH₂)₂—Rf

CH₂═C(—F)—C(═O)—O—(CH₂)₂—SO₂—Rf

CH₂═C(—F)—C(═O)—O—(CH₂)₂—SO₂—(CH₂)₂—Rf

CH₂═C(—F)—C(═O)—NH—(CH₂)₂—Rf

CH₂═C(—Cl)—C(═O)—O—(CH₂)₂—S—Rf

CH₂═C(—Cl)—C(═O)—O—(CH₂)₂—S—(CH₂)₂—Rf

CH₂═C(—Cl)—C(═O)—O—(CH₂)₂—SO₂—Rf

CH₂═C(—Cl)—C(═O)—O—(CH₂)₂—SO₂(CH₂)₂—Rf

CH₂═C(—Cl)—C(═O)—NH—(CH₂)₂—Rf

CH₂═C(—CF₃)—C(═O)—O—(CH₂)₂—S—Rf

CH₂═C(—CF₃)—C(═O)—O—(CH₂)₂—S—(CH₂)₂—Rf

CH₂═C(—CF₃)—C(═O)—O—(CH₂)₂—SO₂—Rf

CH₂═C(—CF₃)—C(═O)—(CH₂)₂—SO₂—(CH₂)₂—Rf

CH₂═C(—CF₃)—C(═O)—NH—(CH₂)₂—Rf

CH₂═C(—CF₂H)—C(═O)—O—(CH₂)₂—S—Rf

CH₂═C(—CF₂H)—C(═O)—O—(CH₂)₂—S—(CH₂)₂—Rf

CH₂═C(—CF₂H)—C(═O)—O—(CH₂)₂—SO₂—Rf

CH₂═C(—CF₂H)—C(═O)—O—(CH₂)₂—SO₂—(CH₂)₂—Rf

CH₂═C(—CF₂H)—C(═O)—NH—(CH₂)₂—Rf

CH₂═C(—CN)—C(═O)—O—(CH₂)₂—S—Rf

CH₂═C(—CN)—C(═O)—O—(CH₂)₂—S—(CH₂)₂—Rf

CH₂═C(—CN)—C(═O)—O—(CH₂)₂—SO₂—Rf

CH₂═C(—CN)—C(═O)—O—(CH₂)₂—SO₂—(CH₂)₂—Rf

CH₂═C(—CN)—C(═O)—NH—(CH₂)₂—Rf

CH₂═C(—CF₂CF₃)—C(═O)—O—(CH₂)₂—S—Rf

CH₂═C(—CF₂CF₃)—C(═O)—O—(CH₂)₂—S—(CH₂)₂—Rf

CH₂═C(—CF₂CF₃)—C(═O)—O—(CH₂)₂—SO₂—Rf

CH₂═C(—CF₂CF₃)—C(═O)—O—(CH₂)₂—SO₂—(CH₂)₂—Rf

CH₂═C(—CF₂CF₃)—C(═O)—NH—(CH₂)₂—Rf

CH₂═C(—F)—C(═O)—O—(CH₂)₃—S—Rf

CH₂═C(—F)—C(═O)—O—(CH₂)₃—S—(CH₂)₂—Rf

CH₂═C(—F)—C(═O)—O—(CH₂)₃—SO₂—Rf

CH₂═C(—F)—C(═O)—O—(CH₂)₃—SO₂—(CH₂₂—Rf

CH₂═C(—F)—C(═O)—NH—(CH₂)₃—Rf

CH₂═C(—Cl)—C(═O)—O—(CH₂)₃—S—Rf

CH₂═C(—Cl)—C(═O)—O—(CH₂)₃—S—(CH₂)₂—Rf

CH₂═C(—Cl)—C(═O)—O—(CH₂)₃—SO₂—Rf

CH₂═C(—Cl)—C(═O)—O—(CH₂)₃—SO₂—(CH₂)₂—Rf

CH₂═C(—CF₃)—C(═O)—O—(CH₂)₃—S—Rf

CH₂═C(—CF₃)—C(═O)—O—(CH₂)₃—S—(CH₂)₂—Rf

CH₂═C(—CF₃)—C(═O)—O—(CH₂)₃—SO₂—Rf

CH₂═C(—CF₃)—C(═O)—(CH₂)₃—SO₂—(CH₂)₂—Rf

CH₂═C(—CF₂H)—C(═O)—O—(CH₂)₃—S—Rf

CH₂═C(—CF₂H)—C(═O)—O—(CH₂)₃—S—(CH₂)₂—Rf

CH₂═C(—CF₂H)—C(═O)—O—(CH₂)₃—SO₂—Rf

CH₂═C(—CF₂H)—C(═O)—O—(CH₂)₃—SO₂—(CH₂)₂—Rf

CH₂═C(—CN)—C(═O)—O—(CH₂)₃—S—Rf

CH₂═C(—CN)—C(═O)—O—(CH₂)₃—S—(CH₂)₂—Rf

CH₂═C(—CN)—C(═O)—O—(CH₂)₃—SO₂—Rf

CH₂═C(—CN)—C(═O)—O—(CH₂)₃—SO₂—(CH₂)₂—Rf

CH₂═C(—CF₂CF₃)—C(═O)—O—(CH₂)₃—S—Rf

CH₂═C(—CF₂CF₃)—C(═O)—O—(CH₂)₃—S—(CH₂)₂—Rf

CH₂═C(—CF₂CF₃)—C(═O)—O—(CH₂)₃—SO₂—Rf

CH₂═C(—CF₂CF₃)—C(═O)—O—(CH₂)₂—SO₂—(CH₂)₂—Rf

wherein Rf is an fluoroalkyl group having 1 to 21 carbon atoms, particularly 1 to 6 carbon atoms.

The fluorine-containing compound (a) can be prepared, for example, as follows.

In case Y is —O— (Oxygen Atom)

Mercaptoethanol is reacted with perfluoroalkyl iodide having a Rf group having one end substituted with iodine in a solvent (for example, water/DMF), for example, at 30° C. to 90° C. for 0.5 hours to 30 hours to give a perfluoroalkyl thioethanol. This alcohol is reacted with dichloropropionic acid in a solvent (for example, cyclohexane) in the presence of a catalyst (for example, paratoluene sulfonic acid), for example, at 30° C. to 70° C. for 0.5 hours to 30 hours to give dichloropropionate. Then, the dehydrochloride reaction is performed in a solvent (for example, chloroform) in the presence of triethylamine to give perfluoroalkylthioethyl (2-chloro)acrylate.

In Case Y is —NH—

Into a reactor, tridecylmethyl ammonium chloride, perfluoroalkylethyl iodide having Rf group substituted with iodine at one end, and an aqueous solution of sodium azide are added (for example, at room temperature), and reacted with stirring and heating (for example, at 50 to 95° C., particularly at 90° C.) for 1 to 50 hours (for example, 20 hours). After the completion of the reaction, the disappearance of the raw material, that is, the iodine compound is confirmed by GC (gas chromatography). The reaction liquid is cooled to room temperature (23° C.), and a lower organic layer is separated. An aqueous layer is extracted with diisopropyl ether, and the extract as such is used in the next reaction.

Into the autoclave, said reaction extract and the catalyst (for example, 10% palladium/carbon) are added and then a hydrogen gas (for example, at the pressure of 2 to 15 Kg/cm², particularly 8 Kg/cm²) is added. The mixture is stirred, for example, at 10 to 30° C. (particularly room temperature (23° C.)) for 1 to 30 hours (for example, 15 hours). The disappearance of the raw material is confirmed by GC, an organic layer is filtered by celite, and a filtrate as such is used in the following reaction.

Into a flask, triethylamine and 4-t-butyl catechol are added to said solution of amino product in diisopropyl ether under cooling with ice. Then 2,3-dichloropropionic acid chloride is added under cooling with ice, and the mixture is stirred at room temperature (23° C.) for 0.5 to 50 hours (for example, 12.5 hours) A produced solid is filtered off, the filtrate is washed with a 5% aqueous solution of citric acid, and the organic layer is dried over magnesium sulfate. The mixture is filtered and the filtrate is concentrated under reduced pressure. A residue is subjected to a silica gel chromatograph to give perfluoroalkylethyl(2-chloro)acrylic acid amide.

A fluorine-containing compound of the formula:

CH₂═C(—X)—C(═O)—NH—(CH₂)_(n)—Rf

-   -   wherein X is a fluorine atom, a chlorine atom, a bromine atom, a         iodine atom, a CFX¹X² group (wherein X¹ and X² is a hydrogen         atom, a fluorine atom or a chlorine atom), a cyano group, a         linear or branched fluoroalkyl group having 1 to 20 carbon         atoms, a substituted or unsubstituted benzyl group, or a         substituted or unsubstituted phenyl group;     -   Rf is a fluoroalkyl group having 1 to 21 carbon atoms; and     -   n is from 0 to 10,         can be prepared by, in the presence of a base (for example, an         organic base or an inorganic base) and in the presence or         absence of a solvent, reacting an amino compound of the formula:

H₂N—(CH₂)_(n)—Rf

wherein Rf is the same as defined above and n is from 0 to 10, with an acid chloride compound of the formula:

A-CH₂—CH(—X)—C(═O)—Cl

-   -   wherein A is a halogen atom (particularly a chlorine atom, a         bromine atom and a iodine atom); and     -   X is a fluorine atom, a chlorine atom, a bromine atom, a iodine         atom, a CFX¹X² group (wherein X¹ and X² is a hydrogen atom, a         fluorine atom or a chlorine atom), a cyano group, a linear or         branched fluoroalkyl group having 1 to 20 carbon atoms, a         substituted or unsubstituted benzyl group, or a substituted or         unsubstituted phenyl group.

Advantageously, this reaction can conduct the amidation and dehydrohalogenation (for example, dehydrochlorination) in one step.

The amount of the acid halide compound may be from 1 mol to 5 mol, based on 1 mol of the amino compound.

Examples of the organic base are trimethylamine, triethylamine, tripropylamine and tributylamine. Examples of the inorganic base are sodium carbonate, potassium carbonate and calcium carbonate.

The amount of the base may be from 1 mol to 10 mol, based on 1 mol of amino compound.

Examples of the solvent are methylene chloride, dichloroethane, acetone, toluene, hexane, cyclohexane, chlorobenzene, ethyl acetate, diisopropyl ether, dimethylformamide and dimethylsulfoxide.

The reaction temperature may be from 0° C. to 100° C. and the reaction time may be from 0.1 hours to 100 hours.

The repeating units (B) are derived from (b) the monomer free from a fluorine atom. The monomer (b) is preferably a fluorine-free monomer having a carbon-carbon double bond. The monomer (b) is preferably a vinyl monomer which is free from fluorine. The fluorine atom-free monomer (b) is generally a compound having one carbon-carbon double bond. Preferable examples of the fluorine atom-free monomer (b) include, for example, ethylene, vinyl acetate, vinyl halide (for example, vinyl chloride) vinylidene halide (for example, vinylidene chloride), acrylonitrile, styrene, polyethyleneglycol (meth)acrylate, polypropyleneglycol (meth)acrylate, methoxypolyethylene-glycol (meth)acrylate, methoxypolypropyleneglycol (meth)acrylate, vinyl alkyl ether and isoprene. The fluorine atom-free monomer (b) is not limited to these examples.

The fluorine atom-free monomer (b) may be a (meth)acrylate ester having an alkyl group. The number of carbon atoms of the alkyl group may be from 1 to 30, for example, from 6 to 30, e.g., from 10 to 30. For example, the fluorine atom-free monomer (b) may be acrylates of the general formula:

CH₂═CA¹COOA²

wherein A¹ is a hydrogen atom or a methyl group, and A² is an alkyl group represented by C_(n)H_(2n+1) (n=1 to 30).

The repeating units (C) are derived from the crosslinkable monomer (c). The crosslinkable monomer (c) may be a fluorine-free monomer having at least two reactive groups and/or carbon-carbon double bonds. The crosslinkable monomer (c) may be a compound having at least two carbon-carbon double bonds, or a compound having at least one carbon-carbon double bond and at least one reactive group. Examples of the reactive group include a hydroxyl group, an epoxy group, a chloromethyl group, a blocked isocyanate group, an amino group and a carboxyl group.

Examples of the crosslinkable monomer (c) include diacetoneacrylamide, (meth)acrylamide, N-methylolacrylamide, hydroxymethyl (meth)acrylate, hydroxyethyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, butadiene, chloroprene and glycidyl (meth)acrylate, to which the crosslinkable monomer is not limited.

The copolymerization with the monomer (b) and/or the monomer (c) can optionally improve various properties such as water- and oil-repellency and soil resistance; cleaning durability and washing durability of said repellency and resistance; solubility in solvent; hardness; and feeling.

In the fluorine-containing polymer, the amount of the fluorine atom-free monomer (b) may be, from 0 to 500 parts by weight, for example, from 0.1 to 100 parts by weight, particularly from 0.1 to 50 parts by weight, and

the amount of the crosslinkable monomer (c) may be from 0 to 50 parts by weight, for example, from 0 to 20 parts by weight, particularly, from 0.1 to 15 parts by weight, based on 100 parts by weight of the fluorine-containing monomer (a).

The weight-average molecular weight of the fluorine-containing polymer may be, for example, from 2,000 to 5,000,000, particularly from 3,000 to 5,000,000, especially from 10,000 to 1,000,000. The weight-average molecular weight of the fluorine-containing polymer can be measured by GPC (gel permeation chromatography) (in terms of polystyrene).

The fluorine-containing polymer can be produced as follows.

In a solution polymerization, there can be used a method of dissolving the monomer(s) into an organic solvent in the presence of a polymerization initiator, replacing the atmosphere by nitrogen, and stirring the mixture with heating at the temperature within the range from 30° C. to 120° C. for 1 hour to 10 hours. Examples of the polymerization initiator include azobisisobutyronitrile, benzoyl peroxide, di-tert-butyl peroxide, lauryl peroxide, cumene hydroperoxide, t-butyl peroxypivalate and diisopropyl peroxydicarbonate. The polymerization initiator may be used in the amount within the range from 0.01 to 20 parts by weight, for example, from 0.01 to 10 parts by weight, based on 100 parts by weight of total of the monomers.

The organic solvent is inert to the monomer(s) and dissolves the monomer(s), and examples thereof include acetone, chloroform, HCHC225, isopropyl alcohol, pentane, hexane, heptane, octane, cyclohexane, benzene, toluene, xylene, petroleum ether, tetrahydrofuran, 1,4-dioxane, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, 1,1,2,2-tetrachloroethane, 1,1,1-trichloroethane, trichloroethylene, perchloroethylene, tetrachlorodifluoroethane and trichlorotrifluoroethane. The organic solvent may be used in the amount within the range from 50 to 2,000 parts by weight, for example, from 50 to 1,000 parts by weight, based on 100 parts by weight of total of the monomers.

In an emulsion polymerization, there can be used a method of emulsifying monomers in water in the presence of a polymerization initiator and an emulsifying agent, replacing the atmosphere by nitrogen, and polymerizing with stirring, for example, at the temperature within the range from 50° C. to 80° C. for 1 hour to 10 hours. As the polymerization initiator, for example, water-soluble initiators (e.g., benzoyl peroxide, lauroyl peroxide, t-butyl perbenzoate, 1-hydroxycyclohexyl hydroperoxide, 3-carboxypropionyl peroxide, acetyl peroxide, azobisisobutyl-amidine dihydrochloride, azobisisobutyronitrile, sodium peroxide, potassium persulfate and ammonium persulfate) and oil-soluble initiators (e.g., azobisisobutyronitrile, benzoyl peroxide, di-tert-butyl peroxide, lauryl peroxide, cumene hydroperoxide, t-butyl peroxypivalate and diisopropyl peroxydicarbonate) are used. The polymerization initiator may be used in the amount within the range from 0.01 to 10 parts by weight based on 100 parts by weight of the monomers.

In order to obtain a polymer dispersion in water, which is superior in storage stability, it is desirable that the monomers are atomized in water by using an emulsifying device capable of applying a strong shattering energy (e.g., a high-pressure homogenizer and an ultrasonic homogenizer) and then polymerized with using the oil-soluble polymerization initiator. As the emulsifying agent, various emulsifying agents such as an anionic emulsifying agent, a cationic emulsifying agent and a nonionic emulsifying agent can be used in the amount within the range from 0.5 to 20 parts by weight based on 100 parts by weight of the monomers. An anionic and/or cationic and/or nonionic emulsifying agent is preferably used. When the monomers are not completely compatibilized, a compatibilizing agent (e.g., a water-soluble organic solvent and a low-molecular weight monomer) capable of sufficiently compatibilizing them is preferably added to these monomers. By the addition of the compatibilizing agent, the emulsifiability and polymerizability can be improved.

Examples of the water-soluble organic solvent include acetone, methyl ethyl ketone, ethyl acetate, propylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol, tripropylene glycol and ethanol. The water-soluble organic solvent may be used in the amount 25 within the range from 1 to 50 parts by weight, e.g., from 10 to 40 parts by weight, based on 100 parts by weight of water. Examples of the low-molecular weight monomer include methyl methacrylate, glycidyl methacrylate and 2,2,2-trifluoroethyl methacrylate. The low-molecular weight monomer may be used in the amount within the range from 1 to 50 parts by weight, e.g., from 10 to 40 parts by weight, based on 100 parts by weight of total of monomers.

The surface treatment agent of the present invention is preferably in the form of a solution, an emulsion or an aerosol. The surface treatment agent generally comprises the fluorine-containing polymer and a medium (particularly an organic solvent and/or water, for example, a liquid medium). The concentration of the fluorine-containing polymer in the surface treatment agent may be, for example, from 0.1 to 50% by weight.

The surface treatment agent can be applied to a substrate to be treated by a know procedure. Usually, the surface treatment agent is diluted or dispersed with an organic solvent or water, is adhered to surfaces of the substrate by a well-known procedure such as an immersion coating, a spray coating and a foam coating, and is dried. If necessary, the surface treatment agent is applied together with a suitable crosslinking agent, followed by curing. It is also possible to add other surface treatment agents (for example, a water repellent agent and an oil repellent agent), or mothproofing agents, softeners, antimicrobial agents, flame retardants, antistatic agents, paint fixing agents, crease-proofing agents, etc. to the surface treatment agent of the present invention. For the immersion coating, the concentration of the fluorine-containing polymer in the treatment liquid contacted with the substrate may be from 0.05 to 10% by weight, based on the treatment liquid. For the spray coating, the concentration of the fluorine-containing polymer in the treatment liquid may be from 0.1 to 5% by weight, based on the treatment liquid. A stain blocker may be used. When the stain blocker is used, it is preferable to use an anionic emulsifier or a nonionic surfactant.

The substrate to be treated with the surface treatment agent (for example, a water- and oil-repellent agent) of the present invention include a textile, masonry, a filter (for example, an electrostatic filter), a dust protective mask, a part of fuel cell (for example, a gaseous diffusion electrode and a gaseous diffusion support), glass, paper, wood, leather, fur, asbestos, brick, cement, metal and oxide, ceramics, plastics, a coated surface and a plaster. The textile may be particularly a carpet. The textile has various examples. Examples of the textile include animal- or vegetable-origin natural fibers such as cotton, hemp, wool and silk; synthetic fibers such as polyamide, polyester, polyvinyl alcohol, polyacrylonitrile, polyvinyl chloride and polypropylene; semi-synthetic fibers such as rayon and acetate; inorganic fibers such as glass fiber, carbon fiber and asbestos fiber; and a mixture of these fibers. The treatment agent of the present invention can be suitably used for carpet made from nylon and/or polypropylene.

The textile may be in any form such as a fiber, a yarn, a fabric and the like. When the carpet is treated with the surface treatment agent of the present invention, the carpet may be formed after treating fibers or yarns with the surface treatment agent, or the formed carpet may be treated with the surface treatment agent.

The “treatment” means that a treatment agent is applied to a substrate by immersion, spraying, coating or the like. The treatment gives the result that a fluorine-containing polymer which is an active component of the treatment agent is penetrated into the internal parts of the substrate and/or adhered to surfaces of the substrate.

EXAMPLES

The following Examples are specifically illustrated but are not to be construed to limit the scope of the invention.

Shower Water Repellency Test

The shower water repellency was expressed by water repellency No. (as shown in the below-described Table 1) conducted according to JIS-L-1092.

TABLE 1 Water repellency No. State 5 No wet or adhesion on surface 4 Slight wet or adhesion on surface 3 Partial wet on surface 2 Wet on surface 1 Complete wet on surface

Water-Repellency Test

A treated fabric is stored in a thermo-hygrostat having a temperature of 21° C. and a humidity of 65% for at least 4 hours. A test liquid (isopropyl alcohol (IPA), water, and a mixture thereof, as shown in Table 2) which has been also stored at 21° C. is used. The test is conducted in an air-conditioned room having a temperature of 21° C. and a humidity of 65%. A droplet of the test liquid in an amount of 0.05 mL is softly dropped by a micropipette on the fabric. If the droplet remains on the fabric after standing for 30 seconds, the test liquid passes the test. The water-repellency is expressed by a point corresponding to a maximum content (% by volume) of isopropyl alcohol (IPA) in the test liquid which passes the test. The water-repellency is evaluated as twelve levels which are Fail, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 in order of a poor level to an excellent level.

TABLE 2 Water-repellency test liquid (% by volume) Isopropyl Point alcohol Water 10 100 0 9 90 10 8 80 20 7 70 30 6 60 40 5 50 50 4 40 60 3 30 70 2 20 80 1 10 90 0 0 100 Fail Inferior to isopropyl alcohol 0/water 100

Oil-Repellency Test

A treated fabric is stored in a thermo-hygrostat having a temperature of 21° C. and a humidity of 65% for at least 4 hours. A test liquid (shown in Table 3) which has been also stored at 21° C. is used. The test is conducted in an air-conditioned room having a temperature of 21° C. and a humidity of 65%. A droplet of the test liquid in an amount of 0.05 mL is softly dropped by a micropipette on the fabric. If the droplet remains on the fabric after standing for 30 seconds, the test liquid passes the test. The oil-repellency is expressed by a maximum point of the test liquid which passes the test. The oil-repellency is evaluated as nine levels which are Fail, 1, 2, 3, 4, 5, 6, 7 and 8 in order of a poor level to an excellent level.

TABLE 3 Oil-repellency test liquid Surface tension Point Test liquid (dyne/cm, 25° C.) 8 n-Heptane 20.0 7 n-Octane 21.8 6 n-Decane 23.5 5 n-Dodecane 25.0 4 n-Tetradecane 26.7 3 n-Hexadecane 27.3 2 Mixture liquid of 29.6 n-Hexadecane 35/nujol 65 1 Nujol 31.2 Fail Inferior to 1 —

Monomers are synthesized as follows.

Synthetic Example 1 9FSECA Monomer Synthesis of 2-(perfluorobutylthio)ethyl 2-chloroacrylate

1,1,1,2,2,3,3,4,4-nonafluoro-4-iodobutane (138.4 g (400 mmol)) was dissolved in a mixture liquid of DMF (400 ml) and water (80 ml), and mercaptoethanol (32.2 g (400 mmol)) was added. Further, sodium formate (27.2 g (400 mol)), sodium sulfite heptahydrate (100.9 g (400 mmol)) were added, and stirred at room temperature (23° C.) for one night. Water (1 L) and isopropyl ether (1 L) were added to the reaction liquid, which was separated. A water layer was further extracted with isopropyl ether (500 ml×2). The organic layer was washed with 10% hydrochloric acid (500 ml), water (500 ml) and a saturated saline solution (500 ml), dried over anhydrous magnesium sulfate and filtered. The solvent was distilled off to give 2-(perfluorobutylthio)ethanol. Then, p-toluene sulfonic acid monohydrate (2.5 g (13.1 mmol)) was added to a solution of 2-(perfluorobutylthio)ethanol (50 g (equivalent to 158 mmol)) and 2,3-dichloropropionic acid (22.5 g (157 mmol)) in cyclohexane (500 ml), and was subjected to dehydration condensation reaction (bath temperature: 90° C.) for one night by using a Dean-Stark method. The reaction liquid was filtered with celite. An organic layer was washed with water three times and with saturated saline solution, and dried over anhydrous magnesium sulfate. The filtration and concentration under reduced pressure gave crude 2-(perfluorobutylthio)ethyl 2,3-dichloropropionate (63.8 g). Yield: 96.5%.

This dichloro product (55 g (131 mmol)) was dropwise added to a solution of chloroform (130 g), triethylamine (15.8 g (157 mmol)) and 4-t-butylcatechol (one particle) with cooling at 0° C. Since the mixture became a solid during the reaction, chloroform (10 g) was added. After dropwise addition, the mixture was stirred at room temperature (23° C.) for 30 minutes, and the disappearance of the raw material was confirmed by GC. The reaction liquid was washed with water, then with a 5% aqueous citric acid, and dried over anhydrous magnesium sulfate. The reaction liquid was filtered and the solvent was distilled off. A fraction of 102 to 104° C./6 mmHg was gathered by the vacuum distillation of the residue to give 2-chloroacrylate ester (41.6 g). Yield: 82.8%.

¹H NMR (CDCl₃; internal standard TMS δ ppm): 6.57 (d, 1H, J_(AB)=1.6 HZ, CH_(A)H_(B)═C), 6.08 (d, 1H, J_(AB)=1.6 HZ, CH_(A)H_(B)═C), 4.47 (t, 2H, J_(HH)=6.6 HZ, OCH₂), 3.27 (t, 2H, J_(HH)=6.6 HZ, CH₂S)

¹⁹F NMR (CDCl₃; internal standard CFCl₃ δ ppm): −82.3 (t, 3 F, J=9.8 Hz, CF₃), −88.4 (m, 2 F, CF₂), −121.8 (m, 2 F, CF₂), −126.7 (m, 2 F, CF₂).

Synthetic Example 2 9FECAM Monomer Synthesis of 2-chloro-N-(3,3,4,4,5,5,6,6,6-nonafluorohexyl)acrylamide

Into a 500 ml flask, an aqueous solution (100 mL) of tridecylmethyl ammonium chloride (2.5 g (10 mmol)), 1,1,1,2,2,3,3,4,4-nonafluoro-6-iodohexane (75 g (200 mmol)) and sodium azide (26 g (400 mmol)) was added at room temperature (23° C.), and heated for 20 hours with an oil bath having the increased temperature of 90° C. while stirring. The disappearance of the raw material, i.e., the iodine compound was confirmed by GC, and then the reaction liquid was cooled to room temperature (23° C.). A lower organic layer was separated and an aqueous layer was extracted with diisopropyl ether (100 ml). Combined organic layers as such were used in the following reaction.

Into a 500 ml autoclave, the above reaction extract (equivalent to 200 mmol) and 10% palladium/carbon (1.5 g) were added, a hydrogen gas was added at the pressure of 8 Kg/cm², and the mixture was stirred at room temperature (23° C.) for 15 hours. The disappearance of the raw material was confirmed by GC, and an organic layer was filtered with celite, the filtrate as such was used in the following reaction.

Into a 500 ml flask, triethylamine (31 ml (300 mmol)) and 4-t-butylcatechol (200 mg) were added to a solution of the above amine product (equivalent to 90 mmol) in diisopropyl ether (300 ml) under cooling with ice, and then 2,3-dichloropropionic acid chloride (16 g (100 mmol)) was dropwise added under cooling with ice, and stirred at room temperature (23° C.) for 12.5 hours. The resultant solid was separated off, the filtrate was washed with a 5% aqueous solution (300 ml) of citric acid, and the organic layer was dried over magnesium sulfate. The mixture was filtered and the filtrate was concentrated under reduced pressure. A residue was subjected to a silica gel chromatograph and purified with n-hexane:ethyl acetate (10:1) to give 2-chloroacrylic acid amide (20 g).

¹H NMR (CDCl₃; internal standard TMS δ ppm): 6.9 (broad s, 1H, NHCO), 6.62 (d, 1H, J_(AB)=1.4 Hz, CH_(A)H_(B)═C), 5.84 (d, 1H, J_(AB)=1.4 HZ, CH_(A)H_(B)═C), 3.70 (AB quartet, 2H, J_(HH)=6.6 Hz, OCH₂), 2.42 (m, 2H, CH₂CF₂)

¹⁹F NMR (CDCl₃; internal standard CFCl₃ δ ppm): −81.5 (t, 3 F, J=10.2 Hz, CF₃), −114.8 (m, 2 F, CF₂), −125.0 (m, 2 F, CF₂), −126.5 (m, 2 F, CF₂).

Polymers were prepared as follows:

Preparative Example 1 9FSECA Homopolymer

Into a 200 mL four-necked flask, the monomer (9FSECA monomer) (10 g (0.026 mol)) prepared in Synthetic Example 1 and butyl acetate (27 g) were charged and nitrogen was flowed for 60 minutes. The temperature of a flask content was increased to 60° C., Perbutyl PV (0.44 g (0.0025 mol)) dissolved in butyl acetate (3.0 g) was added, and the reaction was conducted for 19 hours. The step control in the reaction was conducted on the basis of a gas chromatography, and the disappearance of monomer peaks was confirmed to determine the reaction termination. Methanol was added to the polymerized solution, and a white separated precipitate was filtered under reduced pressure and dried in a vacuum desiccator to give a white powder (8.4 g) (Polymer yield 84%). The polymer was identified by elemental analysis (Table 4).

Preparative Example 2 9FSECA/StA Copolymer

Into a 200 mL four-necked flask, the monomer (9FSECA monomer) (5 g (0.013 mol)) prepared in Synthetic Example 0.1, stearyl acrylate (StA) (2.1 g (0.0065 mol)) and butyl acetate (19.2 g) were charged and nitrogen was flowed for 60 minutes. The temperature of a flask content was increased to 60° C., Perbutyl PV (0.11 g (0.0006 mol)) dissolved in butyl acetate (1 g) was added, and the reaction was conducted for 8 hours. The step control in the reaction was conducted on the basis of a gas chromatography, and the disappearance of monomer peaks was confirmed to determine the reaction termination. Methanol was added to the polymerized solution, and a white separated precipitate was filtered under reduced pressure and dried in a vacuum desiccator to give a white powder (6.3 g) (Polymer yield 90%). The polymer was identified by elemental analysis (Table 4).

Preparative Example 3 9FECAM/StA Copolymer

Into a 200 mL four-necked flask, the monomer (9FECAM monomer) (5.00 g (0.014 mol)) prepared in Synthetic Example 2, stearyl acrylate (StA) (2.1 g (0.0065 mol)) and butyl acetate (19.2 g) were charged and nitrogen was flowed for 60 minutes. The temperature of a flask content was increased to 60° C., Perbutyl PV (0.1 g (0.0006 mol)) dissolved in butyl acetate (1 g) was added, and the reaction was conducted for 10 hours. The step control in the reaction was conducted on the basis of a gas chromatography, and the disappearance of monomer peaks was confirmed to determine the reaction termination. Methanol was added to the polymerized solution, and a white separated precipitate was filtered under reduced pressure and dried in a vacuum desiccator to give a white powder (6.0 g) (Polymer yield 85%). The polymer was identified by elemental analysis (Table 4).

Comparative Preparative Example 1 9FA Homopolymer

Into a 200 mL four-necked flask, 2-(perfluorobutyl)ethyl acrylate (9F-Alc/AA) (R-1420 manufactured by Daikin Chemical Sales, Ltd.) (15 g (0.047 mol)) and tetrachlorohexafluorobutane (121 g) were charged. The solution was bubbled with nitrogen for 30 minutes and then nitrogen was replaced in gas phase for 30 minutes. The temperature of a flask content was increased to 60° C., Perbutyl PV (1.61 g (0.0092 mol)) dissolved in trichloroethane (7.86 g) was added, and the reaction was conducted for 5.5 hours. The step control in the reaction was conducted on the basis of a gas chromatography, and the disappearance of monomer peaks was confirmed to determine the reaction termination. After the completion of the reaction, methanol was added to the polymerized solution, and a white starch syrup-like precipitate was separated. A supernatant liquid was removed off by decantation and the solvent was removed by setting the precipitate in an evaporator to distill off the solvent, whereby giving a very viscous transparent liquid substance (9.36 g) (Polymer yield 82%). The polymer was identified by elemental analysis (Table 4).

Comparative Preparative Example 2 9FA/StA Copolymer

Into a 100 mL four-necked flask, 2-(perfluorobutyl)ethyl acrylate (9F-Alc/AA) (R-1420 manufactured by Daikin Chemical Sales, Ltd.) (7.00 g (0.022 mol)), stearyl acrylate (StA) (3 g (0.093 mol)) and tetrachlorohexafluorobutane (56.47 g) were charged. The solution was bubbled with nitrogen for 30 minutes and then nitrogen was replaced in gas phase for 30 minutes. The temperature of a flask content was increased to 60° C., Perbutyl PV (0.75 g (0.0043 mol)) dissolved in trichloroethane (3.67 g) was added, and the reaction was conducted for 6 hours. The step control in the reaction was conducted on the basis of a gas chromatography, and the disappearance of the 9F-Alc/AA and stearyl acrylate monomer peaks was confirmed to determine the reaction termination. After the completion of reaction, methanol was added to the polymerized solution to give a white precipitate. A supernatant liquid was removed off by decantation and the solvent was removed by setting the precipitate in an evaporator to distill off the solvent, whereby giving a very viscous white opaque liquid substance (7.06 g) (Polymer yield 70.6%). The polymer was identified by elemental analysis (Table 4).

Example 1

The polymer (1.5 g) obtained in Preparative Example 1 was dissolved in HCFC-225 (150 g). After one nylon test fabric (510 mm×205 mm) was immersed in this test solution (150 g) for about 5 minutes, and the solvent was removed by centrifugal dehydrator (500 rpm, 30 seconds). The same procedure was conducted for one PET test fabric (510 mm×205 mm), one PET/cotton mixture test fabric (510 mm×205 mm) and one cotton test fabric (510 mm×205 mm). Then each test fabric was dried at 28° C. for one night.

Then, each one fabric from the nylon test fabric, the PET test fabric, the PET/cotton mixture test fabric and the cotton test fabric was treated by a pin tenter at 150° C. for 3 minutes, and each fabric was cut into halves (255 mm×205 mm). One half was used for a shower water repellency test, and the other half was used for a water repellency test and an oil repellency test. The test results are shown in Table 5.

Example 2

The polymer obtained in Preparative Example 2 was treated as in Example 1 with changing the solvent to butyl acetate, and then subjected to the shower water repellency test, the water repellency test and the oil repellency test. The test results are shown in Table 5.

Example 3

The polymer obtained in Preparative Example 3 was treated as in Example 1 with changing the solvent to methyl isobutyl ketone, and then subjected to the shower water repellency test, the water repellency test and the oil repellency test. The test results are shown in Table 5.

Comparative Example 1

The polymer obtained in Comparative Preparative Example 1 was treated as in Example 1, and then subjected to the shower water repellency test, the water repellency test and the oil repellency test. The test results are shown in Table 5.

Comparative Example 2

The polymer obtained in Comparative Preparative Example 2 was treated as in Example 1, and then subjected to the shower water repellency test, the water repellency test and the oil repellency test. The test results are shown in Table 5.

TABLE 4 Elemental Analysis F C H N Cl Found Calcd. Found Calcd. Found Calcd. Found Calcd. Found Calcd. (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) Preparative 43.27 45.12 28.28 28.08 1.68 1.68 0.00 0.00 9.48 9.21 Example 1 Preparative 29.77 31.99 40.94 42.65 4.13 5.11 0.00 0.00 7.54 6.47 Example 2 Preparative 45.43 48.56 30.24 30.70 2.08 2.15 3.88 3.98 9.05 10.18 Example 3 Comparative 49.43 53.77 33.11 33.96 2.47 2.20 0.00 0.00 0.00 0.00 Preparative Example 1 Comparative 35.91 37.64 48.06 47.11 4.84 5.24 0.00 0.00 0.00 0.00 Preparative Example 2

TABLE 5 Example 1 Example 2 Shower Shower Test water Water Oil Test water Water Oil fabric repellency repellency repellency fabric repellency repellency repellency Nylon 100 3 3 Nylon 100 6 4 PET 100 4 3 PET 100 4 3 PET/ 70 3 3 PET/ 80 4 4 Cotton Cotton Cotton 70 4 3 Cotton 70 6 2 Example 3 Shower Test water Water Oil fabric repellency repellency repellency Nylon 100 4 3 PET 100 4 3 PET/ 80 4 3 Cotton Cotton 80 5 3 Comparative Example 1 Comparative Example 2 Shower Shower Test water Water Oil Test water Water Oil fabric repellency repellency repellency fabric repellency repellency repellency Nylon 50 3 0 Nylon 70 4 2 PET 70 3 3 PET 50 4 3 PET/ 0 3 3 PET/ 50 4 2 Cotton Cotton Cotton 0 Fail 3 Cotton 0 4 2 

1-16. (canceled)
 17. A fluorine-containing polymer comprising (A) repeating units derived from a fluorine-containing compound (a): CH₂═C(—X)—C(═O)—Y—[—(CH₂)_(m)-Z-]_(p)—(CH₂)_(n)—Rf  (a) wherein X is a fluorine atom, a chlorine atom, a bromine atom, a iodine atom, a CFX¹X² group (wherein X¹ and X² is a hydrogen atom, a fluorine atom or a chlorine atom), a cyano group, a linear or branched fluoroalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted benzyl group, or a substituted or unsubstituted phenyl group; Y is —O— or —NH—; Z is —S— or —SO₂—; Rf is a fluoroalkyl group having 1 to 21 carbon atoms; m is from 1 to 10, n is from 0 to 10, and p is 0or
 1. 18. The fluorine-containing polymer according to claim 17, further having: (B) repeating units derived from (b) a monomer free from a fluorine atom, and (C) optionally, repeating units derived from (c) a crosslinkable monomer, in addition to the repeating units (A).
 19. The fluorine-containing polymer according to claim 17, wherein the fluorine atom-free monomer (b) forming the repeating units (B) is acrylates of the general formula: CH₂═CA¹COOA² wherein A¹ is a hydrogen atom or a methyl group, and A² is a hydrocarbon group having 1 to 30 carbon atoms (particularly an alkyl group represented by C_(n)H_(2n+1) (n=1 to 30)).
 20. The fluorine-containing polymer according to claim 18, wherein the crosslinkable monomer (c) forming the repeating units (C) is a fluorine-free monomer having at least two reactive groups and/or carbon-carbon double bonds.
 21. The fluorine-containing polymer according to claim 18, wherein the amount of the fluorine atom-free monomer (b) is 0.1 to 50 parts by weight, and the amount of the crosslinkable monomer (c) is at most 20 parts by weight, based on 100 parts by weight of the fluorine-containing compound (a).
 22. A surface treatment agent comprising the fluorine-containing polymer according to claim 17 and water and/or an organic solvent.
 23. The surface treatment agent according to claim 22, which is in the form of a solution, an emulsion or an aerosol.
 24. A method of treating a substrate with the surface treatment agent according to claim
 22. 25. The method according to claim 24, wherein the substrate is a textile, a masonry, a filter (for example, an electrostatic filter), a dust protective mask, a fuel cell, glass, paper, wood, leather, fur, asbestos, brick, cement, metal and oxide, ceramics, plastics, a coated surface or a plaster.
 26. A textile treated with the surface treatment agent according to claim
 22. 27. A carpet treated with the surface treatment agent according to claim
 22. 28. A method of producing a fluorine-containing compound of the formula: CH₂═C(—X)—C(═O)—NH—(CH₂)_(n)—Rf wherein X is a fluorine atom, a chlorine atom, a bromine atom, a iodine atom, a CFX¹X² group (wherein X¹ and X² is a hydrogen atom, a fluorine atom or a chlorine atom), a cyano group, a linear or branched fluoroalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted benzyl group, or a substituted or unsubstituted phenyl group; Rf is a fluoroalkyl group having 1 to 21 carbon atoms; and n is from 0 to 10, said method comprising, in the presence of a base, reacting an amine compound of the formula: H₂N—(CH₂)_(n)—Rf wherein Rf is the same as defined above and n is from 0 to 10, with an acid chloride compound of the formula: A-CH₂—CH(—X)—C(═O)—Cl wherein A is a halogen atom (particularly a chlorine atom, a bromine atom or a iodine atom); and X is a fluorine atom, a chlorine atom, a bromine atom, a iodine atom, a CFX¹X² group (wherein X¹ and X² is a hydrogen atom, a fluorine atom or a chlorine atom), a cyano group, a linear or branched fluoroalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted benzyl group, or a substituted or unsubstituted phenyl group. 